tinkerer said:frasera
You can get small (36") sections of aluminium rod stock at Home Depot. They come in various diameters. I'm a packrat by nature & neccessity so I pick up any metal pieces I see at junkyards or dumpsters for projects. My scrap pile probably weighs close to 1,000 lbs. I get alot of "cut offs" at metal suppliers. These are the pieces less than a foot and sold cheap.
You can probably find a piece at home depot thats close enough in diameter to a AA cell to use without turning on a lathe. just cut to size. allow some room to wrap with electrical tape on the sides.